Could your ex be violent? Here are warning signs to look out for.

Last Thursday, a Montclair, NJ-based mom named Monica Paul was shot and killed at close range in front of her 11-year-old daughter at a local YMCA during her child's swimming lessons. The murderer was Paul's ex.

According to police, the two parents argued right before Kenneth A. Duckett, 37, shot Paul, 31, three or four times at 6:30 p.m. inside the Helen and Bill Geyer YMCA Family Center.

Paul had been sitting with her daughter in a waiting area outside the pool where her 4-year-old son was swimming. Afterward, Duckett (who has two children with Paul) ran out of the building and jumped into a white Jeep with an unidentified man.

"Right now, we are fairly confident in saying it appears to be a targeted incident that was directed at this poor individual," Essex County Prosecutor Paula T. Dow said. "It doesn't appear to be random--he seemed to be going after her."

Monica Paul knew Duckett was dangerous--she had taken out a restraining order against him last year. But had Paul always feared Duckett, or did his violent behavior appear out of the blue?

"It's unlikely a woman would marry a man she believed to be dangerous," says Jane Greer, Ph.D., a marriage and family therapist in New York City. "In the beginning of a relationship, it's easy to ignore the warning signs of abuse and focus on the positive aspects of a person. After all, you're on a romantic hormonal high so everything he does seems wonderful."

What's more, people are not just two-dimensional. We all occasionally act in ways we're ashamed of, and nobody is perfect. And sometimes relationships go through rough patches and it can be difficult to gauge between someone behaving poorly and legitimate abuse. However, Dr. Greer says to be aware of specific signs a person is capable of hurting you. If your spouse or ex exhibits any of these behaviors, seek help immediately.

• Explosive anger or violence (i.e.: throws objects, is physically aggressive)
• Blocks exits or hides car keys to prevent leaving
• Isolates you from family and friends or otherwise limits your contact with the outside world
• Emotional abuse (name calling, ridicule, frequent criticism)
• Disregards your feelings and has a complete focus on their own needs

"The problem is, for many women, abuse is an ongoing cycle, and even if they acknowledge what's going on, they may feel it's their fault--especially if the aggressor has worked hard to make it seem that way," says Greer. "And because the woman thinks his behavior is her responsibility to fix, she won't take proper safety precautions."

And oddly enough, many times controlling behavior can feel like love. For instance, if your spouse complains when you spend time with your friends and family, at first it may seem flattering ("He wants me all to himself!"). However, Greer says this is a sign he wants to remove your support system so you have no one to turn to--except for him.

If you see these warning signs, Greer says to disengage from the relationship right away. "Leave with your children, then call to let him know you won't be returning and clearly--but briefly--tell him why," she says. "Don't confront him in person--otherwise, he'll likely try to stop you."

If you fear he'll track down your family, don't stay with them, but make sure loved ones know where you are and have ways to reach you. To get support or to find a shelter in your area, click here.